The 1916 Brusilov Offensive proved to be the worst crisis of World War I for Austria-Hungary, and the Triple Entente's greatest victory. But it came at a tremendous loss of life for both sides. And without the promised support of Russia's other armies, much of the territory gained by Brusilov was lost to the Germans arriving from the west. It is a sad irony that in the end, it was a political collapse in Russia, not a military defeat, that would decide the outcome of this region's war.